juplo.de Git - juplo-dialect/blob - src/main/java/de/juplo/thymeleaf/ImportVariablesAttrProcessor.java

   1 package de.juplo.thymeleaf;
   2
   3
   4 import com.fasterxml.jackson.core.JsonFactory;
   5 import de.juplo.jackson.SimpleMapper;
   6 import java.io.IOException;
   7 import java.io.InputStream;
   8 import java.util.Iterator;
   9 import java.util.Locale;
  10 import java.util.Map.Entry;
  11 import org.slf4j.Logger;
  12 import org.slf4j.LoggerFactory;
  13 import org.thymeleaf.Arguments;
  14 import org.thymeleaf.Configuration;
  15 import org.thymeleaf.TemplateProcessingParameters;
  16 import org.thymeleaf.context.IContext;
  17 import org.thymeleaf.context.VariablesMap;
  18 import org.thymeleaf.dom.Element;
  19 import org.thymeleaf.processor.ProcessorResult;
  20 import org.thymeleaf.processor.attr.AbstractAttrProcessor;
  21 import org.thymeleaf.resourceresolver.IResourceResolver;
  22 import org.thymeleaf.templateresolver.ITemplateResolver;
  23 import org.thymeleaf.templateresolver.TemplateResolution;
  24
  25
  26
  27 /**
  28  * Retrievs and parses JSON-data and imports the parsed variables as node-local
  29  * variables.
  30  * @author Kai Moritz
  31  */
  32 public class ImportVariablesAttrProcessor extends AbstractAttrProcessor
  33 {
  34   public static final int ATTR_PRECEDENCE = 200;
  35
  36   private static final Logger LOG =
  37       LoggerFactory.getLogger(ImportVariablesAttrProcessor.class);
  38   private static final JsonFactory FACTORY = new JsonFactory();
  39
  40
  41   public ImportVariablesAttrProcessor()
  42   {
  43     super("variables");
  44   }
  45
  46
  47   @Override
  48   public final ProcessorResult processAttribute(
  49       final Arguments arguments,
  50       final Element element,
  51       final String name
  52       )
  53   {
  54     Configuration config = arguments.getConfiguration();
  55     String templateName = element.getAttributeValue(name);
  56
  57     TemplateProcessingParameters params =
  58         new TemplateProcessingParameters(
  59             config,
  60             templateName,
  61             new IContext() // << We will not execute the template, hence we need no context
  62             {
  63               @Override
  64               public VariablesMap<String, Object> getVariables()
  65               {
  66                 return new VariablesMap<>();
  67               }
  68
  69               @Override
  70               public Locale getLocale()
  71               {
  72                 return Locale.getDefault();
  73               }
  74
  75               @Override
  76               public void addContextExecutionInfo(String templateName)
  77               {
  78               }
  79             });
  80
  81     for (ITemplateResolver t_resolver : config.getTemplateResolvers())
  82     {
  83       TemplateResolution resolution = t_resolver.resolveTemplate(params);
  84       if (resolution == null)
  85         continue;
  86       if (!"JSON".equals(resolution.getTemplateMode()))
  87         continue;
  88       IResourceResolver r_resolver = resolution.getResourceResolver();
  89       InputStream is =
  90           r_resolver.getResourceAsStream(params, resolution.getResourceName());
  91       if (is == null)
  92         continue;
  93
  94       try
  95       {
  96         Iterator<Entry<String, Object>> it =
  97             SimpleMapper.getObjectIterator(FACTORY.createParser(is));
  98         while(it.hasNext())
  99         {
 100           Entry<String, Object> entry = it.next();
 101           element.setNodeLocalVariable(entry.getKey(), entry.getValue());
 102         }
 103       }
 104       catch (IOException e)
 105       {
 106         LOG.error("cannot retreive {} as JSON: {}", templateName, e.getMessage());
 107         throw new RuntimeException(e);
 108       }
 109       catch (IllegalArgumentException e)
 110       {
 111         LOG.error("cannot parse {} as JSON: {}", templateName, e.getMessage());
 112         throw new RuntimeException(e);
 113       }
 114     }
 115
 116     element.removeAttribute(name);
 117
 118     return ProcessorResult.OK;
 119   }
 120
 121
 122   @Override
 123   public int getPrecedence()
 124   {
 125     return ATTR_PRECEDENCE;
 126   }
 127 }